The present invention relates generally to bicycle derailleurs, and more particularly, is directed to a bicycle derailleur with mechanism for adjusting the spring tension thereof.
A conventional rear derailleur for a bicycle includes a first pivot axis at the derailleur head which is secured to the bicycle frame and a second pivot axis at the derailleur cage. A spring is provided in association with each of the pivot axes in order to balance the derailleur to achieve a correct angular position thereof. In order to vary the angular position of the derailleur, it is necessary to provide an adjustment of the spring tension of at least one of the springs.
Generally, it is better to provide the adjustment at the derailleur head, rather than the derailleur cage. This is because adjustment at the derailleur cage requires a trial and error adjustment, in which the user grabs and holds the derailleur stationary while making the adjustment, and then releases the derailleur to determine the angular movement caused by such adjustment. This may occur several times by trial and error. On the other hand, since the derailleur head is secured to the bicycle frame, the user can make such adjustment while immediately viewing any change in angular orientation of the derailleur. This makes any adjustment of the spring pressure easier at the derailleur head.
Various arrangements have been provided for adjusting the spring pressure at the derailleur head. These arrangements allow the user to make the spring adjustment at an inboard location of the derailleur. However, the inboard location is a tight location and it can be difficult to make the adjustment thereat.